void SCSChannelManagerFragmentProgram::merge()
{
GLuint vId = OpenGL::getARBVertexProgram(mergeVertexProgram, (sizeof(mergeVertexProgram) / sizeof(mergeVertexProgram[0])) - 1);
glBindProgramARB(GL_VERTEX_PROGRAM_ARB, vId);
glEnable(GL_VERTEX_PROGRAM_ARB);
GLuint fId =
isRectangularTexture()
? OpenGL::getARBFragmentProgram(mergeFragmentProgramRect, (sizeof(mergeFragmentProgramRect) / sizeof(mergeFragmentProgramRect[0])) - 1)
: OpenGL::getARBFragmentProgram(mergeFragmentProgram2D, (sizeof(mergeFragmentProgram2D) / sizeof(mergeFragmentProgram2D[0])) - 1);
glBindProgramARB(GL_FRAGMENT_PROGRAM_ARB, fId);
glEnable(GL_FRAGMENT_PROGRAM_ARB);
bool isFixedFunction = false;
setupProjectiveTexture(isFixedFunction);
glEnable(GL_ALPHA_TEST);
glEnable(GL_CULL_FACE);
glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_LESS);
glDepthMask(GL_TRUE);
glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);
glAlphaFunc(GL_LESS, 1.0f / 255.0f);
std::vector<Channel> channels;
channels.push_back(AllChannels);
for (std::vector<Channel>::const_iterator c = channels.begin(); c!=channels.end(); ++c) {
scissor->recall(*c);
scissor->enableScissor();
const std::vector<Primitive*> primitives = getPrimitives(*c);
for (std::vector<Primitive*>::const_iterator j = primitives.begin(); j != primitives.end(); ++j) {
glCullFace((*j)->getOperation() == Intersection ? GL_BACK : GL_FRONT);
RenderData* primitiveData = getRenderData(*j);
GLubyte * id = primitiveData->bufferId.vec();
glColor4ubv(id);
(*j)->render();
}
}
scissor->disableScissor();
glDisable(GL_ALPHA_TEST);
glDisable(GL_CULL_FACE);
glDepthFunc(GL_LEQUAL);
glDisable(GL_FRAGMENT_PROGRAM_ARB);
glDisable(GL_VERTEX_PROGRAM_ARB);
resetProjectiveTexture(isFixedFunction);
clear();
}
void cSceneManager::renderEntitySingleShader(cShader* shader, std_string const& technique, cEntityModel const* entity)
{
if (!shader)
return ;
if (!entity)
return ;
cRenderData* rd = getRenderData(entity->getRenderDataBuid());
if (!rd)
return ;
uint pass;
shader->setTechnique(technique.c_str());
shader->begin(&pass);
renderRdShader(shader, pass, rd);
shader->end();
}
void SCSChannelManagerAlphaOnly::merge() {
bool isFixedFunction = true;
setupProjectiveTexture(isFixedFunction);
glEnable(GL_ALPHA_TEST);
glEnable(GL_CULL_FACE);
glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_LESS);
glDepthMask(GL_TRUE);
glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);
std::vector<Channel> channels = occupied();
for (std::vector<Channel>::const_iterator c = channels.begin(); c!=channels.end(); ++c) {
setupTexEnv(*c);
scissor->recall(*c);
scissor->enableScissor();
const std::vector<Primitive*> primitives = getPrimitives(*c);
for (std::vector<Primitive*>::const_iterator j = primitives.begin(); j != primitives.end(); ++j) {
glCullFace((*j)->getOperation() == Intersection ? GL_BACK : GL_FRONT);
RenderData* primitiveData = getRenderData(*j);
GLubyte id = primitiveData->bufferId.a;
// Here is an interesting bug, which happened on an ATI HD4670, but actually
// might happen on every hardware. I am not sure whether it can be solved
// correctly.
// Problem is that in optimized mode with some compilers (VC6, Visual Studio 2003
// in particular), when setting the alpha func as follows:
// glAlphaFunc(GL_EQUAL, static_cast<float>(id) / 255.0f);
// the division is optimized as multiplication with 1.0f/255.0f.
// This is a fine and valid optimization. Unfortunately, the results
// are not exactly the same as the direct division for some ids.
// Which is apparently what the ATI driver is doing internally.
// So with comparison with GL_EQUAL fails.
// Fortunately the OpenGL standard enforces that the mapping of color byte
// values to float fragment values be done by division. So if the
// solution found below (just working at double precision) proves
// to work once, it should work forever, such that a precompiling
// lookup table containing the correct alpha reference values is
// not required. However a bad feeling remains.
// The SCSChannelManagerFragmentProgram path implemented below should fix this.
double alpha = static_cast<double>(id) / 255.0;
GLfloat fAlpha = static_cast<float>(alpha);
glAlphaFunc(GL_EQUAL, fAlpha);
(*j)->render();
}
}
scissor->disableScissor();
glDisable(GL_ALPHA_TEST);
glDisable(GL_CULL_FACE);
glDepthFunc(GL_LEQUAL);
resetProjectiveTexture(isFixedFunction);
clear();
}
